为了降低多输入多输出正交频分复用(multiple input multiple output orthogonal frequency division multiplexing,MIMO-OFDM)系统中传统部分传输序列(partial transmit sequence,PTS)算法的计算复杂度,提出了联合时域和空间域信号处...为了降低多输入多输出正交频分复用(multiple input multiple output orthogonal frequency division multiplexing,MIMO-OFDM)系统中传统部分传输序列(partial transmit sequence,PTS)算法的计算复杂度,提出了联合时域和空间域信号处理的改进PTS算法。在时域信号处理部分,通过信号子块循环移位实现备选序列的增加;在空间域部分,利用天线间信号子块交换实现峰均功率比(peak to average power ratio,PAPR)抑制。同时在接收端,利用子块相位旋转引起的相位差异,本方法通过比较接收信号与星座点的距离,可以实现信号的盲检测,从而有效提高MIMO-OFDM系统的频谱利用率。仿真结果表明,提出的方法能有效地抑制MIMO-OFDM信号的PAPR,而且明显降低了传统PTS算法的计算复杂度,同时可获得跟传统PTS方法已知边带副信息时相似的比特误码率(bit error rate,BER)性能。展开更多
在滤波器组多载波(Filter Bank Multicarrier,FBMC)系统中,通常采用部分传输序列(Partial Transfer Sequence,PTS)方法来降低系统的峰均功率比(Peak-to-Average Power Ratio,PAPR),然而该方法在传输过程中需要携带边带信息,会降低频谱...在滤波器组多载波(Filter Bank Multicarrier,FBMC)系统中,通常采用部分传输序列(Partial Transfer Sequence,PTS)方法来降低系统的峰均功率比(Peak-to-Average Power Ratio,PAPR),然而该方法在传输过程中需要携带边带信息,会降低频谱利用率.对此提出了两点改进:在搜索最佳相位因子时,提出了新多层搜索方法,避免了相位因子的重复搜索,降低了计算复杂度;通过加入改进星座映射(Active Constellation Extension,ACE)方法,在接收端可以不需要边带信息即可快速解调出原始数据,虽然PAPR有所增加,但却显著提高了频谱利用率.通过计算和仿真验证了两个改进方案的有效性.展开更多
The high peak-to-average power ratio (PAPR) is one of the serious problems in the application of OFDM technology. In this paper, an improved partial transmit sequence (PTS) scheme based on combining the grouped discre...The high peak-to-average power ratio (PAPR) is one of the serious problems in the application of OFDM technology. In this paper, an improved partial transmit sequence (PTS) scheme based on combining the grouped discrete cosine transform (DCT) with PTS technique is proposed. In the proposed scheme, the adjacent partitioned data are firstly transformed by a DCT into new modified data. After that the proposed scheme utilizes the conventional PTS technique to further reduce the PAPR of the OFDM signal. The performance of the PAPR is evaluated using a computer simulation. The simulation results indicate that the proposed scheme may improve the PAPR performance compared with the conventional PTS scheme, the grouped DCT scheme, and original OFDM respectively.展开更多
Wavelet packet multicarrier system gains widespread concern because of its better resistance performance to Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), as well as the higher spectrum efficien...Wavelet packet multicarrier system gains widespread concern because of its better resistance performance to Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), as well as the higher spectrum efficiency. However, multicarrier system has a high Peak to Average Power Ratio (PAPR), which will lead to many problems such as lower system performance. In order to solve the problem, a kind of PAPR reduction method based on pruning Wavelet Packet Modulation (WPM) and Partial Transmit Sequences (PTS) technology is proposed in this paper, through proper pruning of the full-tree structure of wavelet packet modulation in the PTS technology to reduce the number of nodes in the system, and finally improve the reduction effect of PAPR. Simulation results show that when Complementary Cumulative Distribution Function (CCDF) is 10 -3 , PTS based on pruning WPM compared with PTS technique and pruning technique has improved about 1 dB and 1.5 dB, which will not affect the system's Bit Error Rate (BER) performance in the wavelet packet multicarrier system.展开更多
[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patient...[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patients with suppressed internal heat.[Methods]Thirty cases of URM patients with suppressed internal heat and 30 normal women were collected,and characteristics of changes in peripheral serum D-dimer(D-D),fibrin degradation product(FDP),fibrinogen(FIB),IL-6,IL-10 and TNF-α,CD,CD,CD,CD,CDlevels were detected.URM patients were treated with traditional Chinese medicine for clearing heat and resolving blood stasis for 3 menstrual cycles,and the changes of indicators before and after treatment were observed.[Results]Compared with normal women,the peripheral serum levels of D-D,IL-6,TNF-αand CDin URM patients with suppressed internal heat were increased(P<0.05),while the IL-10 lymphocyte level was significantly decreased(P<0.05);compared with that before treatment,the contents of D-D,IL-6,TNF-αand CDdecreased after 3 menstrual cycles(P<0.05),while the contents of IL-10 and CDT lymphocytes increased significantly(P<0.05).[Conclusions]The heat clearing heat and stasis resolving method can effectively improve the prethrombotic state of URM,and the action mechanism may be related to the regulation of immune and peripheral blood inflammatory factors.展开更多
Partial Transmit Sequences (PTS) is an efficient scheme for Peak-to-Average Power Ratio (PAPR) reduction in Orthogonal Frequency Division Multiplexing (OFDM) system. It does not bring any signal distortion. However, i...Partial Transmit Sequences (PTS) is an efficient scheme for Peak-to-Average Power Ratio (PAPR) reduction in Orthogonal Frequency Division Multiplexing (OFDM) system. It does not bring any signal distortion. However, its remarkable drawback is the high computational complexity. In order to reduce the computational complexity, currently many PTS methods have been proposed but with the cost of the loss of PAPR performance of the system. In this paper, we introduce an improved PTS optimization method with superimposed training. Simulation results show that, compared with conventional PTS, improved PTS scheme can achieve better PAPR performance while be implemented with lower computation complexity of the system.展开更多
部分传输序列(Partial Transmit Sequence,PTS)是降低正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统峰均比(Peak-to-Average Power Ratio,PAPR)的有效方法,但是PTS穷举法搜索最优解,使系统复杂度增加。针对这一...部分传输序列(Partial Transmit Sequence,PTS)是降低正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统峰均比(Peak-to-Average Power Ratio,PAPR)的有效方法,但是PTS穷举法搜索最优解,使系统复杂度增加。针对这一缺点进行改进,提出了基于离散粒子群优化的部分传输序列(Partial Transmit Sequence based on Discrete Particle Swarm Optimization,PTS-DPSO)方法,并将其应用到基于偏移正交幅度调制的滤波器组多载波系统(Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation,FBMC/OQAM)中。PTS-DPSO利用离散粒子群优化搜寻最优解,避免了系统复杂度的增加。通过仿真验证,PTS-DPSO可以有效抑制FBMC/OQAM系统过高的PAPR且误码率低。展开更多
文摘为了降低多输入多输出正交频分复用(multiple input multiple output orthogonal frequency division multiplexing,MIMO-OFDM)系统中传统部分传输序列(partial transmit sequence,PTS)算法的计算复杂度,提出了联合时域和空间域信号处理的改进PTS算法。在时域信号处理部分,通过信号子块循环移位实现备选序列的增加;在空间域部分,利用天线间信号子块交换实现峰均功率比(peak to average power ratio,PAPR)抑制。同时在接收端,利用子块相位旋转引起的相位差异,本方法通过比较接收信号与星座点的距离,可以实现信号的盲检测,从而有效提高MIMO-OFDM系统的频谱利用率。仿真结果表明,提出的方法能有效地抑制MIMO-OFDM信号的PAPR,而且明显降低了传统PTS算法的计算复杂度,同时可获得跟传统PTS方法已知边带副信息时相似的比特误码率(bit error rate,BER)性能。
文摘在滤波器组多载波(Filter Bank Multicarrier,FBMC)系统中,通常采用部分传输序列(Partial Transfer Sequence,PTS)方法来降低系统的峰均功率比(Peak-to-Average Power Ratio,PAPR),然而该方法在传输过程中需要携带边带信息,会降低频谱利用率.对此提出了两点改进:在搜索最佳相位因子时,提出了新多层搜索方法,避免了相位因子的重复搜索,降低了计算复杂度;通过加入改进星座映射(Active Constellation Extension,ACE)方法,在接收端可以不需要边带信息即可快速解调出原始数据,虽然PAPR有所增加,但却显著提高了频谱利用率.通过计算和仿真验证了两个改进方案的有效性.
文摘The high peak-to-average power ratio (PAPR) is one of the serious problems in the application of OFDM technology. In this paper, an improved partial transmit sequence (PTS) scheme based on combining the grouped discrete cosine transform (DCT) with PTS technique is proposed. In the proposed scheme, the adjacent partitioned data are firstly transformed by a DCT into new modified data. After that the proposed scheme utilizes the conventional PTS technique to further reduce the PAPR of the OFDM signal. The performance of the PAPR is evaluated using a computer simulation. The simulation results indicate that the proposed scheme may improve the PAPR performance compared with the conventional PTS scheme, the grouped DCT scheme, and original OFDM respectively.
文摘Wavelet packet multicarrier system gains widespread concern because of its better resistance performance to Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), as well as the higher spectrum efficiency. However, multicarrier system has a high Peak to Average Power Ratio (PAPR), which will lead to many problems such as lower system performance. In order to solve the problem, a kind of PAPR reduction method based on pruning Wavelet Packet Modulation (WPM) and Partial Transmit Sequences (PTS) technology is proposed in this paper, through proper pruning of the full-tree structure of wavelet packet modulation in the PTS technology to reduce the number of nodes in the system, and finally improve the reduction effect of PAPR. Simulation results show that when Complementary Cumulative Distribution Function (CCDF) is 10 -3 , PTS based on pruning WPM compared with PTS technique and pruning technique has improved about 1 dB and 1.5 dB, which will not affect the system's Bit Error Rate (BER) performance in the wavelet packet multicarrier system.
基金Supported by National Natural Science Foundation of China(81760806)Project of Traditional Chinese Medicine Administration of Gansu Province(GZK-2019-28)Innovation Ability Improvement Project of Higher Education Institutions of Gansu Province(2019B-103)。
文摘[Objectives]To explore the effects of heat clearing and stasis resolving method on prethrombotic state,inflammatory factors and T-lymphocyte subsets in peripheral blood of unexplained recurrent miscarriage(URM)patients with suppressed internal heat.[Methods]Thirty cases of URM patients with suppressed internal heat and 30 normal women were collected,and characteristics of changes in peripheral serum D-dimer(D-D),fibrin degradation product(FDP),fibrinogen(FIB),IL-6,IL-10 and TNF-α,CD,CD,CD,CD,CDlevels were detected.URM patients were treated with traditional Chinese medicine for clearing heat and resolving blood stasis for 3 menstrual cycles,and the changes of indicators before and after treatment were observed.[Results]Compared with normal women,the peripheral serum levels of D-D,IL-6,TNF-αand CDin URM patients with suppressed internal heat were increased(P<0.05),while the IL-10 lymphocyte level was significantly decreased(P<0.05);compared with that before treatment,the contents of D-D,IL-6,TNF-αand CDdecreased after 3 menstrual cycles(P<0.05),while the contents of IL-10 and CDT lymphocytes increased significantly(P<0.05).[Conclusions]The heat clearing heat and stasis resolving method can effectively improve the prethrombotic state of URM,and the action mechanism may be related to the regulation of immune and peripheral blood inflammatory factors.
文摘Partial Transmit Sequences (PTS) is an efficient scheme for Peak-to-Average Power Ratio (PAPR) reduction in Orthogonal Frequency Division Multiplexing (OFDM) system. It does not bring any signal distortion. However, its remarkable drawback is the high computational complexity. In order to reduce the computational complexity, currently many PTS methods have been proposed but with the cost of the loss of PAPR performance of the system. In this paper, we introduce an improved PTS optimization method with superimposed training. Simulation results show that, compared with conventional PTS, improved PTS scheme can achieve better PAPR performance while be implemented with lower computation complexity of the system.
文摘部分传输序列(Partial Transmit Sequence,PTS)是降低正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)系统峰均比(Peak-to-Average Power Ratio,PAPR)的有效方法,但是PTS穷举法搜索最优解,使系统复杂度增加。针对这一缺点进行改进,提出了基于离散粒子群优化的部分传输序列(Partial Transmit Sequence based on Discrete Particle Swarm Optimization,PTS-DPSO)方法,并将其应用到基于偏移正交幅度调制的滤波器组多载波系统(Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation,FBMC/OQAM)中。PTS-DPSO利用离散粒子群优化搜寻最优解,避免了系统复杂度的增加。通过仿真验证,PTS-DPSO可以有效抑制FBMC/OQAM系统过高的PAPR且误码率低。
